A series of CaMoO 4 :xTb 3+(x=0.01,0.03,0.05,0.07,0.09,0.15 and 0.20) phosphors in pure phase were prepared via high temperature solid-state reaction approach.The crystal structure of the phosphors was investigated by X-ray diffraction(XRD),and the optical properties were investigated by Fourier transform infrared spectroscopy(FT-IR),ultraviolet-visible spectroscopy(UV-Vis) and photoluminescence(PL) spectroscopy.The PL spectra illustrated that these phosphors could be efficiently excited by the charge transfer band of the host and the energy transfer efficiency from the host to the doped activator reached 60% when the doping concentration of the activator Tb 3+ was 20 mol.%.The concentration quenching occurred at x=10 mol.%,from which the critical distance of activator was calculated to be about 1.14 nm.The CIE coordinates were estimated to be close to the standard green value.The host sensitized samples had potential application as green phosphors.
A series of LiY1-xEux(MoO4)2 red-emitting phosphors were synthesized by sol-gel technique. The phase impurity and spectroscopic properties were characterized by X-ray diffraction (XRD) and photo-luminescence (PL) spectra respectively. The effect of Eu3+ doping con-centration, annealing temperature and the molar ratio of citric acid to the total metal cations (C:M) on the optical properties of the red phos-phors were studied and optimized. It was found that all the samples could be excited efficiently by blue light (465 nm), which was well coin-cident with the emission of GaN based LED chips. The luminescent intensity reached maximum when annealing temperature was 750 ?C and Eu3+ doping concentration was 5% with C:M=3:1.
